Electric percussion tool



Oct. 30, 1934. J. R. TAYLOR ELECTRIC PERCUSSION TOOL Filed April 14, 1953 2 Sheets-Sheet a I 4 O T 4 o 3 NH 4 a w 6 7 i z 0 5 n all x: 4 W I I V Y Y u 2 B in M? 2 M u l||\ J I -PIHHH 4 a ,0 i 2 .2 g 3 m m, 5 U 7 6 5 a 2 3 k2 M 3 U 6 ll O 4 W l1 7 w 6 AM: \L/ |1 |l||| I Z W 5 7 7 3 3 a 5 e 2 2 5 d .4 2 2 2 d 3 A TTORNE YS.

Oct. 30, 1934.

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u III 1/IIIIII 1 7IIIIIIIIIIUIIYIIIIIIYIIIII AIIlIA'I/[I/ J. RITAYLOR ELECTRIC PERCUSSION TOOL Filed April 14, 1953 2 Sheets-Sheet 2 zmgfjo INVENTOR.

ATTORNEYS.

$4005 E. Zinc 6 Patented Oct. 30, 1934 "UNITED STATES? PATENT OFFICE 1,978,442 ELECTRIC PERCUSSION TOOL JacobR." Taylor, San Francisco, Calif. I 1 Application April 14, 1933, serial No. 666,158 13 Claims. (01.1172-426) This invention relates to reciprocating'motors and particularly to electric percussion tools.

object of the invention is to provide an eflicient driving mechanism for percussion tools and the like, wherein a reciprocating-element is employed for the production of work, the working element being reciprocated by the alternative setting up of electromagnetic fields inspa'ced solenoids.

further object of the invention is to provide a non-magnetic guide through spaced sole noids, yet to provide means whereby the respectivemagneticfields can act on a plunger core for reciprocating the latter in said guide; a circuit breaker being provided adjacent the guide for actuation by the plunger core, whereby the spaced solenoids are alternately energized.

Anotherobject of the invention is to provide a circuit breaker in an electricpercussion tool for alternately energizing spaced solenoids thereby to reciprocatea core means being provided on the core and the circuit breaker forpositiv ely operating the circuit breaker at each stroke of the core and to hold the circuit breaker in position throughout each stroke of the core.

A still further object'of the invention is to provide an energy absorption structure for percussion tools whereby an air cushion is utilized to absorb the energy of each idle stroke of the plunger ,core. f 1

Other objects ,anclfladvantages are to provide an electric reciprocating motor and electric ipercussion tool that will be-supericr in pointof simplicity, ineirpensiveness .of construction positiveness of operation and facility and convenience in use and general efficiency.

In this specification and the annexed drawings, the invention is illustrated in the form considered to be the best, but itisto be understood that the inventionisnot limitedto such form, because it may be embodiedin other forms; and :it is also to be understood that in and by the claims following the description, it is desired to coverthe invention in whatsoever form it may be embodied.

This. invention is clearly illustrated in the ac.- companying drawings wherein, Y

Figure 1 is a siderview of an electric percussion tool constructed in accordance with myinvention and being shown partly in section.

Figure 2 is .a fragmental sectional view of .my electric percussion tool.

Figure 3 is .a iragmental sectional view of my electric percussion tool showing the plunger at 55 the end of itsback stroke. f v

Figure 4 is a detailed view of .a circuit breaker mechanism, and

s Figure 5 is a fragmental view on an enlarged scale of thezcontacts and actuator of the circuit breaker mechanisinon the guide.

In carryingvout my invention, I make use of a housing 1, which may .be made .of either magnetic or non-.magneticx'material in my device. The housing 1 is substantially cylindrical. ,In the housing 1 is removably placed an-electromagneticfield producing structure and a reciprocating core system.

The electric-magnetic from producing structure comprises two solenoids 2 and 3 spaced from each other endwisely. Each of the solenoids 2 and 3 is preferably made of a winding of coils 4 around, 1 a bushing 5 of magnetic material, but it may be iormedin another suitable manner.

The reciprocating core system includes a tubular member 6, preferably made of non-magnetic material. I The member 6 extends through the .bushings fiof .both solenoids, and also beyond the solenoids '2 and 3 at both ends thereof. The tubular member 6 forms a guide withinwhich a plunger core 7 reciprocates. :The length of the 0 core '7 is slightly larger than twice the height of one of said solenoids, and the spacing between the solenoids 2 and 3 is slightly larger than the height of one of said solenoids. The tubular member 6 has aslits8 substantially along its en- 35 tire length to allow forthe action of the magnetic fields of the solenoids 2 and 3 onthe core '7. The core' '7 is preferably made of magnetic material, because the usual non-magnetic materials do not'standsup .under the blows on the tool as well as certain magnetic materials. The outer diameter of the cored is smaller than the inner diameter of the tubularmember 6 and is spaced from said member. The core '1 is guided in the member 6 by means of collars 9, 10, and 11 thereon which slidably fit within the tubular member 6. The collars 9 and 11 are at the opposite ends of the plunger .core '7; while the collar 10 is intermediate between the ends of said core 7. The shoul ders 12 of the collars 9 and 11 and the shoulders 1 13 of the collar 10 arein definite, spaced relation for the operation of a circuit breaker. mechanism 14 mountedon the outside of the tubular memher 6.

There is a spacer sleeve or bushing 15 on the outside portion of the tubular member 6 between the opposedends of the solenoids 2 and 3, to positively space the solenoids2 and 3 apart and prevent the sliding. of .the solenoidstoward each other. The sleeve 15 has a. slit 16 on one side is pivotally mounted intermediate its ends on a pivot 19 on the bracket 17. The lever 18 is opposite to andaligned with the slits 8 and 16.

On the opposite end of the lever 18 are fiat substantially V shaped points 20 and 21 which slidably fit into the slits 8 and 16, and extend through said slits to protrude into the interior or the tubular member 6 and in the path of thecollars 9, 10, and 11 of the core 7. The spacing of the points 20 and 21 from each other corresponds to the spacing between one of the shoulders 12 points 20 and 21 are between two adjacent shoulders 12 and 13 at the end of each stroke of the plunger core '7. As the plunger core 7 reciprocates it oscillates the lever 18 at each stroke by reason of the successive engagements of the points 20 and21 by the respective shoulders 12 and 13 of the collars 9, 10, and 11. I From the lever 18 extend lateral abutment prongs 22and 23 in' opposite directions. The prong '22 is located between the point 20 and the pivot 19, and the prong 23 is between .the point 21 and said pivot 19. Opposite to and below. each prong 22 and 23 is a lug24 extended from the sleeve 15. On the lug 24 is .a stationary contact I 25, anda spring contact 26. When theilever 18 is tilted the prong '22 or 23, as the case may be,

is pressed against the adjacent spring contact .26 and closes the same against the stationary contact 25 therebelow, thereby closing an electric circuit.

A wire or conductor 27 connects each stationary contact 25 to the nearest solenoid 2 or 3. The wires 28 lead from the spring contacts 26 to the top of thehousing to connect to a terminal of a source ofv electricity. i

Each solenoid .2 and 3 is also connected to a wire 29 and toanother terminal of the source of electricity not shown. Whenoneof. the spring contacts 26 is depressed by reason of the tilting of the lever 18 the solenoid nearest to said contact 26 is energized and the core 7is drawn thereinto. At the end of the strokeof the core 7 one of the end collars of the core 7 again tilts the lever 18 and causes the pressing of the other spring con tact 26 into circuit closing position, thereby the other solenoid is energized and the core 7 is again reciprocated.

In order to prevent the lever 18 from tilting, by reason of the tension of the closed spring contact 26, .a spring. washer 29 is provided on the pivot 19 and is suitably pressed against the lever 18 at the pivot to resist any accidental tilting of said lever 18.. It requires a positive exertion. of force on the ends of .the lever 18 to tilt'it.

The aforedescribed field core system, and circuit breaker are assembled as a unit, hte entire unit beingreadily removable. from the housing 1. This unit is held in place in the housing 1 by a tool holder 30 at one end and I bya cover 38 at the other end of the housing 1.

The tool holder 30 is threadedly secured in place as at 32, and it has an a'xiallbore 33 there-' through. Theinner end of the bore 33 is counterbored or recessed at 34 toaccommodate the end of the tubular member 6 therein. It is to closing position.

producing structure,

be noted that the lower end of the tubular member 6 abuts against the bottom of the counterbore or recess 34, and the said recess 34 is substantially of the same depth as the length of the portion of the tubularmember 6 extended beyond the solenoid 3, so that the solenoid 3 rests upon the inner end of the holder 30. The shank 35 of a tool 36 slidably fits into the bore 33 of the holder 30. The shank 35 has a stop or collar 37 adjustably fixed thereon to determine the length of the shank 35 extended into the holder. The top of the shank 35 extends above the bottom of the recess and into the end of the tubular member 6 in the path of the lower end 11 of the core '7. The tool 36 may be made either of steel, or of soft iron with a steel head on the inner end of the shank 35.

A cover 38 is threadedly secured in the other end of the housing 1. The cover 38 has a recess v w i or pocket 39 formed therein into which the upper and the adjacent shoulder 13, so that the two end of the tubular member 6 extends. The depth of the pocket 39 is such as to accommodate the part of the tubular member 6 extended beyond the solenoid 2 so that the inner end of the cover 38 bears against the solenoid 2. In this manner the solenoids 2 and 3, and the tubular member 6 are positively held within the housing 1. It is to be noted that the pocket 39 is not provided with any air escapadhence on the backward or idle stroke of the plunger core '7 air is compressed into the pocket 39 forming an air cushion, and energy absorbing means.

On the cover 38 is secured a handle 40 of the usual type. The handle 40 is preferably provided with a cavity therein through which. extend wires 41 and 42. Wire 41 is connected to wires 28, and the wire 42 is connected to the solenoids. A hand switch 43 of the usual trigger type is connected in series with wire 41 to control the supply of current to the field producing system.

A flexible cord 44 is provided to conduct electricity to the said wires. In operation the housing '1 and the handle 40 are gripped by the operator in the usual manner, so that the tool 36 is held against the Work. Then the operator closes the trigger switch 43. The plunger core 7 by reason of its own gravity assumes a position shown inFig. 1, when not in operatiomhence the lever 18 is so tilted that the point 20 and the prong 22 are held in circuit Consequently the solenoid 2 is energizedfirst and attracts the plunger core '7 upwardly against the air cushion in the pocket 39. The energy of this stroke is thus absorbed. The solenoid 2 remains energized throughout the entire" backward stroke of the plunger core '7. As the middle collar 10 of the core 7 passes the point 20 it pushes the same outwardly of the tubular member 6, thereby it tilts the lever 18 and moves the other point 21 into the tubular member6 and in the path of the otherend collar 11. The shoulder 12 of the end collar 11 holds the point 21 in place, the point 20 being at the same time in an out of way position. Thus the prong 22 .is raised to allow the spring contacts 'therebelow to break the electric circuit of the prong 22 upon the-spring contact therebelow to energize solenoid 2. Inthis manner thesolenoids, 2 and -3 are alternately'energized, and remain energized for the respective full" strokes of the core 7, because the circuit breaker i4 is positively actuated by thecore 7 at the completion of each stroke. The electrical driving'mechanism herein described operates with equal eiliciency on direct current as well as on alternating current; its operation is positive, and powerful, yet the construction is simple, and itreadily adaptesitself for use by labor ordinarilyavailable.

Having thus described this invention, what I claim and desire to secure by. Letters Patent is: 1. In a reciprocating electric motor a housing, field producing means, a reciprocating core system, and a guide of non-magnetic material to guide said core extended along the entire length oi! the stroke of said core system, 'said'guide having a longitudinal slit along a side thereof communicating with the air in the housing to prevent-suction and compression in the path of the reciprocating core system.

2. In a reciprocating electric motor a housing, a pair of spaced solenoids, a reciprocating core system, and a'guide of non-magnetic material to guide said core extended through both solenoids, said guide having a longitudinal slit along a side thereof, an oscillating circuit breaker disposed between the spaced solenoids to cause alternate energization of said field producing means, and means related to said circuit breaker to coact through said slit with the reciprocating core to actuate the circuit breaker at the completion of each stroke of the core.

3. In a reciprocating electric motor a pair of spaced solenoids, a reciprocating core, a guide extended through the solenoids to guide said reciprocating core; an element tiltably supported on the guide, a normally open circuit breaker connected in series with each solenoid, means on said element to alternately close the circuit breakers as the element is tilted in opposite directions; said guide having a longitudinal slit on a side thereof, abutments on said element being slidably extended through said slit, and means on the reciprocating core to coact with said abutments to tilt the element at each stroke of the reciprocating core.

4. In a reciprocating electric motor the combination with a pair of spaced solenoids, a reciprocating core, a guide extended through the solenoids to guide said reciprocating core; of an element tiltably supported on the guide intermediate its ends, normally open circuit breakers one for each solenoid, means on said "element to alternately engage and close the respective circuit breakers as the element is tilted in opposite directions; said guide having a longitudinal slit on a side thereof, abutments on said element being slidably extended through said slit, and means on the reciprocating core to coact with said abutments to tilt the element at each stroke of the reciprocating core; said coacting means on the core being adapted to maintain the element tilted until the completion of the respective strokes of the core.

5. In a reciprocating electric motor the combination with a pair of spaced solenoids, connected to a source of electricity, a reciprocating core, and a guide for the core extended through the solenoids; of a circuit breaker mechanism comprising a rocking element on the guide; said guide having a longitudinal slit along its side, spaced abutments extended from said element through said slit, normally open circuit breakers one foreach solenoid, means on the rocking element to alternately close the respective circuit breakers when rocked in opposite directions, and means on the core to coact with said abutments to rock said element once at each stroke of the reciprocating core. g

6. In a reciprocatingelectric motor the combination with ,a pair of spaced solenoids, connected to a source of electricity, a reciprocating core, and a guide for the core extended through the solenoids; of a circuit breaker mechanism comprising a rocking element on the guide; said guide having a longitudinal slit along its side, spaced abutments extended from said element through said slit, a normally open circuit breaker operatively connected to each solenoid, means on the rocking" element to alternately close the circuit breakers when rocked in opposite directions; and a plurality of abutment members on the core spaced from each other, the spacing between said abutment members being substantially equal to the length of one stroke of the reciprocating core, said abutment members being adapted to engage the respective abutments of the rocking element to rock said element at the completion of each stroke of the reciprocating core.

'7. In a reciprocating electric motor, the combination with a pair of spaced solenoids, a guide extended through the solenoids, a core reciprocated in said guide; of a circuit breaker mechanism between the spaced solenoids, comprising a rockable element fulcrumed on the guide to extend longitudinally with respect to the guide,

said guide having a longitudinal slit along a side thereof in operative position relatively to said rockable element, a normally open circuit breaker on each side of the fulcrum connected to each solenoid and being in operative relation to said rockable element, a pair of spaced abutments extended from the rockable element and through the slits, said abutments being on opposite sides of the fulcrum of the rockable element, means on said element to alternately close the respective circuit breakers when rocked in opposite directions; a plurality of spaced members on the core adapted to coact with said abutments in opposite directions as the core reciprocates.

8. In an electric percussion tool, the combination with a pair of spaced solenoids on a guide in a housing having a core in the guide reciprocated by said solenoids and means to alternately energize the solenoids, a head at one end of the housing, a holder at the other end of the housing, of opposed, aligned recesses in the head and tool holder, the ends of the guide being extended into said recesses, the end of the guide in said head being adapted to cooperate with said recess in the head to confine an air pocket therein completely closed by the end of the core at the end i of a stroke thereof, the remaining portion of the guide being open to allow the passage of air into and out of the interior of the guide.

9. In an electric percussion tool, the combination with a pair of spaced solenoids on a guide in a housing having a core in the guide reciprocated by said solenoids and means to alternately energize the solenoids, a head at one end of the housing, a tool holder at the other end of the housing, of opposed, aligned recesses in the head and tool holder the ends of the guide being extended into said recesses, said guide having a longitudinal slit through a side thereof extending from the end of the tool holder recess to a point in the recess in the head spaced from the bottom of the recess to confine an airpo'cket in the head at an end of the stroke of said core.

10. In a reciprocating electric motor the combination' with electromagnetic field producing means, a reciprocating core, means to guide the core through said field producing means, and means to cause the energization of said field producing means so as to reciprocate thecore, of means to form a compression chamber at an'end of said guiding -means, and means to conduct air into and out of said guide means as the core is reciprocated, said conducting means being inoperative relatively to said compression chamber.

11. In a reciprocating electric motor the com bination with field producing means, a guide'extended through said means, and a core reciprocated in said guide by the alternate energization of said field producing means, of means to form a cushioning chamber at an end of said guide, and means to communicate the portions of the guide that extend into the field producing means with the surrounding 1 space in the motor so as to allow circulationof air into and from said guide as the core is reciprocated.

12. The combination with a percussion: tool including a, core reciprocated by electromagnetic means in a guide, and a tool opposite the end of one stroke of the core, of a compression chamber formed at the end of the guide adjacent the end of the other-stroke of the core being adapted to receive'air urged into said chamber by the core, said guide having a passage formed on its side to conduct air into and from the interior of the guide as the core is reciprocated, said passage being closed relatively to said compres f',

sion chamber by the action of said core near the end of the second stroke of the core.

13. The combination with a percussion tool including a core reciprocated by electromagnetic means in a guide, and a tool'opposite the end of one stroke of the core, of a compression chamber formed at the end of the guide adjacent the end of the other stroke of the core being adapted to receive air urged into said chamber by the core, the side of said guide being slotted at points below said compression chamber to allow pas.- sage of air into and out of the path of the reciprocated core when the end of the core is outside of said compression chamber.

JACOB R. TAYLOR. 

